Variable displacement fluid apparatus



April 7, 1953 A. R. PARILLA ErAL 2,633,802

VARIABLE DISPLACEMENT FLUID APPARATUS R -ffnaem April 7, 1953 A. R. PARILLA Erm.

VARIABLE DISPLACEMENT FLUID APPARATUS Filed 061;. 13, 1947 INVENTOR. ARTHUR l2 .PARlLLn By ANTHONY PETER Patented Apr. 7, 1953 VARIABLE DISPLACEMENT FLUID APPARATUS Arthur R. Parilla, Dearborn, Mich., and Anthony Peters, New York, N Y.

Application October 13, 1947, Serial No. 779,586

6 Claims. (Cl. 10S-38) Our invention relates to fluid apparatus adapted to serve as a pump or motor, and this application is a continuation in part of our copending application Serial No. 545,346 led July 17, 1944, now Patent No. 2,428,809.

An object of this invention is to provide control means operative to vary the uid displacement of the apparatus and thus to regulate the volume of fluid passed therethrough.

f Another object is to provide in a fluid apparatus having pistons reciproeable and rotatable by end contact with wobble plates or the like, means coupling the wobble plates and pistons in a manner to insure positive reciprocal movement of the pistons at all times during the actuation of the wobble plates and without impedance to rotary movement of the pistons.

Otherl objects include'those comprised in our prior copending application above identified as well as those apparent to persons skilled in the art.

In the drawings:

Figure 1 is substantially a vertical longitudinal section through the apparatus;

Figure 2 is a section taken on the line 2-2 of Figure 1;

Figure 3 is a section taken on the line 3-3 of Figure 1;

Figure 4 is a section taken on the line 4-4 of Figure 1;

Figure 5 is a section taken on the line 5-5 of Figure 1;

Figure 6 is a fragmentary elevation of the outer end portion of a piston forming anelement of the assembly;

Figure 7 is an elevation similar to Figure 6 but illustrating an alternative embodiment of piston end structure;

Figure 8 is a fragmentary elevation similar to Figure 7 but illustrating a further alternative embodiment of piston end structure;

` Figure 9 is a longitudinal vertical section of an alternative structural embodiment of the apparatus.

' In the embodiment of the apparatus shown in Figure l the structure comprises an axially bored, cylindrical, sectional housing including a combined main body and end section I0, an intermediate manifold section II, and an end section I2 held in assembled relation by end cap housings I3 and I4 secured by tie bolts I5. A shaft I6 extends axially through the sections and is journalled on roller bearings I'I in the end sections I0 and. I2.l The shaft I6 extends at one end Ventirely through the cap housing I4 to' 2 provide an external end I8 arranged for operative connection with power take-011 or input means, not shown. At its other end the shaft is provided with a tongue I9 having two parallel plane side faces 20 chordal to the perimeter of the shaft. The tongue is preferably an integral part of the shaft and extends fully into but not through the end cap I3.

As in our said prior application, the housing assembly is provided with a circumferential series of equidistantly spaced bores arranged radially of the shaft receiving bore with their axes parallel thereto. Each bore mounts a cylinder liner 2| open from end to end and comprising a single unit coextensive in length with the length of the assembled housing sections I9, II and I2.

Within the confines of the cap I4 the shaft I6 has keyed or otherwise suitably mounted thereon a fixed angle wobble plate 22 having an inclined rotary bearing plate 23 carried by the outer race 24 of a ball bearing assembly forming a part of the wobble plate structure. At the other end of the apparatus within the cap I3 the shaft tongue I9 has pivotally mounted thereon a variable angle wobble plate 25 similar to the wobble plate 22 in that it carries a rotary bearing plate 26 on the outer race 21 of its ball bearing assembly. g With reference to Figure `3, it will be seen that the wobble plate 25 pivots on a pin 28 disposed transversely through the shaft tongue I9 with its axis perpendicular to the axis of the shaft. On its outer face the plate is formed With a pair of rounded ribs or projecting elements 29 arranged in diametrically opposed relation in a plane disposed at right angles to the axis of the pivot pin 28.

Control means for varying the angle of inclination of the wobble plate 25 to regulate the output or input of the apparatus is disposed in the cap housing I3. In the present embodiment of our invention the means comprises a double planetary gear train. The outer set has an outer ring gear 30 xed on the cap I3 by appropriate securing means 3|. The sun gear 32 is fixed to the shaft tongue I9 for rotation with the shaft I6 and drives at its R. P. M. the planet gears 33. Those gears 33 are journalled on a spider 34 that isfreely rotatable on the shaft tongue and which carries the planet gears 35 of the inner set. The ring gear 36 of the inner set is normally locked by meshed engagement with a Worm gear on an actuator crank 3l which extends externally of the housing for manual or other operation. yThe planet gears 35 drive the sun gear 38 which is mounted for rotary shifting movement with respect to the shaft tongue I9 in a direction dependent upon actuation of the worm crank 31. The second sun gear 38 is provided on its inner face with an annular cam 39 having an inclined bearing surface continuously in contact with the rounded ribs 29 ofi thefvariablewobble"plate: By thisl arrangementirelative rotary shifting'of the lcam 39 varies the angle of inclination of the wobble plate and thus alters the stroke of pistons re-VY ciprocable in the cylinders 2l.

Each cylinder liner 2I receives"'a^pair^'ofpisal tons 40 and 4I operatively engaged at their outer ends by the wobble plates in'z'afmannerto effect simultaneous reciprocation and rotation of the-JV The pistons 40 at the variable wobble pistons. plate end of the apparatus are relatively shorter in length than the pistons 4I and are counterspective conduitports L48V and vl9 through .whichr iiuid is admitted to orpassed from the apparatus.

Preferably, the pistons liI are provided 'with4 rings 50.

AsV shown in Figure 6, the outer end of ,each

piston is formed with a reduced neck 5I terminating in a T-head 52-having enlarged cylindrical ends 53. The length of the head is somewhat greater than thediameter of the piston, and theV cylindrical surfaces of the portions53 are in line bearing contact against the bearing plate 23 or 23 of the adjacent wobble plate. thiscontact, which is continuousthe.. inclination of the wobble plate operatesas the wobble plate isrotated-to reciprocate thepistons and at the same ltime to rotate them for valving the fluid ports.V In order to insure positive outward movement'of the pistons under all conditions or" their expansion stroke operation `we provide on the wobble plate adjacent each pistona spring clip 54 suitably aixed rigidly to thewobble plate or its bearing plate. v The springclip is bifurcated toprovide arms 55 which arev engaged behind the cylindrical portions 53 of .the T-head Vonfthe. end of the adjacent piston. These arms 55 function to impart a positive outward pull tothe pistons on their expansion strokes and, as they straddle the pistons, they present no interference to rotation of the pistons.

, AnV alternative embodiment of piston end 1s shown in Figure 7 in which the outer end of the piston` d0 is tapered invfrusto-conical form' and terminates in a plane contact face 56 having a diameter smaller than the diameterof the' piston. The smalljbearing surface 56 is fully adequate when in contact with the bearing plate 'of the wobble plate to insure the necessary rotation'and reciprocation of the piston. Figure 8 illustrates a Yfurther alternative embodiment of piston end in which the pistondcis'provided with a cross head 51 similar tothe cross. head 52shown in Figure 6. In 4the embodiment ofFigure 8 the axis of thevcrosshead 51 is at right angles to the axis of the piston .and iseccentric withlrespect to` the By reason vvof tothe interior ofthe cylinder. As in the precedaxis of the piston. This construction provides for a highly efficient line contact of the piston and with the adjacent wobble plate.

In the embodiment of the invention illustrated in Figure 9 the apparatus utilizes only one wobble plate which is variable for adjustment as in the form shown in Figure 1. The embodiment shown inFigure Q-YhassubStantially` the same arrangement of shaft i6 with .its 'reduced :tongue I9 mounting the variable wobble plate 25. The inclination of the wobble plate is adjusted by the same planetary gear mechanism and the elements are designated by the same reference characters as those employed in Figure 1. In this embodimentthe end cap housing I3 is provided with aiiuid port 58 through which iiuid is admitted to orpassed from the apparatus. The cap is fixed to a'body casing 59 which is provided with a iiuid port k6B in communication with a cylinder 6I provided in the casing. A piston 62 slidably and rotatably mounted in the cylinder end at its other end fis provided with the same connection of cross head 53 and spring clip 54 illustrated in the embodiment of Figure 1. The piston 62 is formed with an axial passage 63 which opens atjthe outer end of the piston into the chamber formed Within' the cap I3.. In the inner end of the passage 63 a check valve 64 is suitably mounted at the inner end of the counterbore 65 of the piston. The

counterbore opens at. the innerend ofthe piston ing embodiment, the piston 62 is provided with a port for. registry with the port69 as the piston is reciprocated and rotated Within the cylinder.' In' the operation of this alternative embodimentl ofthe apparatus, vthe iiuid is passed through' the body Yof the pistonY past the check valve vwhich' I5 the piston stroke` becomes shorter. When the-l wobbleV plate isdisposed-at a rightl angle tothe shaft axis the set of pistons 49 is at zero strokel andthe Vdisplacement is atfone-half its -maximum value, as the stroke of the opposed set of'A pistons isfixed.v If the adjusting movement ofV the variable wobble plate is continued until itst angle of inclination parallels Athat ofthe iixed wobble plate all pistons will be moving unidirectionally and the net displacement Willbe'zero.

If` the inclination'of the variablewobble plate is" continued beyond the angle of zero displacement it will reverse the'iiowpf'uidthrough the apparatus.

Portvalving is accomplished vby rotation of ther` constant stroke pistons'and-no ports/arevr required in the variable stroke'pistons except in' the alternative embodiment shown in .Figure 9.' The pistons 40. may be solid ifr desired.y

We claim:

l. Fluid apparatus comprising a cylinder hav-f ing an inlet port. andA an outlet port, a pistonrotatable, and reciprocable therein ,to 'control'at" least one of said ports,V a rotatablelelement'inclined .Withrespect to the cylinder` axis' anddirectly abutting an end of the piston for rotating and reciprocating the pistonas saidv element is rotated cam means slidably engagingand nor-f mally rotating with said inclined element, and' mechanism for shifting said'camt'means relativeto said inclined element. duringrotationz'ofthe two whereby to vary the angle of inclination of said element and alter the stroke of the piston.

2. Fluid apparatus comprising cylinders having inlet and outlet ports, a pair of opposed pistons rotatable and reciprocable in each cylinder, one set of pistons controlling the ports by rotation, an inclined element rotatable at a iixed angle of inclination relative to the port controlling pistons, means provided for said port controlling pistons bearing against said inclined element for imparting rotation to the pistons as the element is rotated, Van inclined element rotatable relative to the other set of pistons and in engagement therewith, said last named element being Variable as to inclination, and control means engaged with said last named element to vary the angle of inclination thereof.

3. Fluid apparatus comprising a cylinder having a port in its wall, a piston rotatable and reciprocable in the cylinder and controlling the port by rotation, the piston having a uid passage opening through its outer end, means for admitting fluid through s-aid passage, a check valve in the passage, an inclined element engaging the outer end of the piston and rotatable to impart rotation and reciprocation to the piston, and means for changing the angle of inclination of said element to vary the stroke of the piston.

4. Fluid apparatus comprising a cylinder, a piston rotatable and reciprocable therein, a shaft rotatable relative to the cylinder, a wobble plate on the shaft and rotatable therewith to actuate said piston, said wobble plate being pivotally mounted on the shaft on an axis at right angles to the shaft axis, control mechanism engaging the wobble plate and shiftable on the shaft for rocking the plate on its pivot to vary its incli- 6 nation relative to the shaft axis, and planetary gear means on the shaft for actuating the control mechanism.

5. The structure of claim 4, and said planetary gear means including a self-locking actuator worm in mesh with a iing gear of the planetary gear.

6. Fluid apparatus comprising a cylinder having a port in its wall, a piston rotatable and reciprocable in the cylinder and controlling the port by rotation, the piston having a fluid passage opening through its outer end, means for admitting fluid through said passage, a check valve in the passage, and an inclined element engaging the outer end of the piston and rotatable to impart rotation and reciprocation to the piston.

ARTHUR R. PARILLA. ANTHONY PETERS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Great Britain 1935 

